Accurate identification of people is critical for law enforcement, as well as for many security and fraud-detection applications in the public and private sectors. Current methods employ high-resolution optical and infrared cameras or scanners to image the face, or read finger prints or iris patterns in the eye. These approaches work with reasonable accuracy but usually require direct (or extremely close) contact with the person to be identified: for example, by placing a hand on the scanner plate to record fingerprints, or placing one's head against a positioning-frame to allow a lens to produce a high-resolution image of the eye.
Identification based on fingerprints has been widely deployed in recent years for security and immigration applications, and is even being used in some computer systems for user login identification. However, such systems are sensitive to the presence of dirt on the fingers, often require reapplication of the finger, and are sensitive to variants such as the pressure of the finger during the fingerprint acquisition process. Fingerprint identification may also be fooled by using artificially gummy fingers. Facial recognition methods on the other hand, are not necessarily limited to very-close range, but the subject must be facing in the direction of a camera since a clear, well-lit image is required. Thus it is relatively easy to evade such systems by wearing a disguise, a face mask, or tilting the head down to avoid providing a clear image of the face. Visual face recognition methods of course depend critically on the quality of the image, which renders such systems sensitive to range and illumination.
In one embodiment, the invention relates to a system for biometrically identifying a person using microwave radiation, the system including at least one processor configured to segment a microwave cardiac signal including cardiac beats into segments, to extract features from the segments, and to perform pattern identification of the segments and features with a pre-existing data set, where the microwave cardiac signal is obtained from reflected microwave radiation including an electrocardiographic waveform and an impedance-cardiographic waveform. In another embodiment, the invention relates to a method for biometrically identifying a person using microwave radiation, the method including segmenting a microwave cardiac signal including cardiac beats into individual segments, where the microwave cardiac signal is obtained from reflected microwave radiation including an electrocardiographic waveform and an impedance-cardiographic waveform, extracting features from the segments, and performing pattern identification of the features in the individual segments with a pre-existing data set.